How do you cope with the “double risk trend” in reliability? (Part 2)
This is the second post in a series of blogs that discusses how to cope with “the double risk” trend in reliability, and how smart transmission and distribution grids can mitigate this risk. In my first blog I introduced the double risk trend and provided some background information on reliability. In this blog I will elaborate on the five factors that highly contribute to this double risk trend, as well as discuss how they will shape the future of the electric power system. These factors include:
1) Increasing age of (most) western power systems
2) Growing complexity and interdependencies
3) Time duration of the planning process for generation plants and transmission & distribution (T&D) infrastructure
4) Geographic distribution of generation and load
5) Flexibility to balance between supply and demand
A majority of the existing power systems in the US and Europe were built decades ago, and are in urgent need of upgrades in order to cope with the challenges of delivering power to the right place at the right time, and with the right reliability and quality. The power system has evolved rapidly into a complex integrated system with many interdependencies. Introductions of new technology help to drive this trend, including: variable wind and solar generation, storage, inverters, and new markets driven by smart meters, advanced controls, and information and communication technology.
Renewable sources, especially at customer locations, are usually built in a short timeframe with realisation times of a few months for small scale systems, to a few years for larger wind and solar farms. Even offshore wind farms can be built within a timespan of five to seven years, while new-build in the transmission and distribution grids require often longer planning cycles; for new transmission capacity this can be more than 10 years. New large (renewable) power plants are continuing to be built at the borders of the grid (this includes offshore), and in remote locations far from the big cities and industry. This trend—combined with the fact that more embedded renewables are installed in rural areas—leads to an increased need for a power grid that is capable of accommodating this spatial distribution. As the wind does not always blow, and the sun does not always shine, the increase in renewable generation calls for a greater flexibility of the power system with more complex and advanced control mechanisms to maintain the balance between supply and demand and to manage the power flows.
In my next blog post I will discuss methods to mitigate the effects of these five factors.